An outboard engine generally comprises a bracket assembly that connects the drive unit of the outboard engine to the transom of a boat. The drive unit includes the internal combustion engine and propeller. The outboard engine is typically designed so that the steering angle and the tilt/trim angles of the drive unit relative to the boat can be adjusted and modified as desired. The bracket assembly typically includes a swivel bracket carrying the drive unit for pivotal movement about a steering axis and a stern bracket supporting the swivel bracket and the drive unit for pivotal movement about a tilt axis extending generally horizontally. The stern bracket is connected to the transom of the boat.
A hydraulic actuator is connected between the swivel bracket and the drive unit for pivoting the drive unit about the steering axis in order to steer the boat. One or more hydraulic actuators are also connected between the stern and swivel brackets for pivoting the swivel bracket to trim the drive unit, to lift the lower portion of the outboard engine above the water level or, conversely, lower the lower portion of the outboard engine below the water level.
The steering motion of the watercraft is controlled by a steering assembly including a steering operator, such as a steering wheel, provided in the watercraft. The steering operator is connected to the hydraulic actuator(s) for steering via a hydraulic assembly including one or more pumps, hydraulic fluid reservoirs, hoses and valves. A power steering assembly is connected to the hydraulic assembly to assist in steering of the watercraft by the steering operator. It is possible for components of the power steering assembly to get overheated during operation of the watercraft.
It is known to protect electric components such as the power steering pump motor from overheating by providing a temperature sensor to monitor the temperature of the pump motor and shutting off the pump motor when the motor reaches a threshold operating temperature. However, abruptly shutting off the power steering pump during operation is undesirable as it will result in a sudden loss of power steering. In such a condition, the operator maintains the ability to steer the watercraft, but steering takes much more effort without the assistance provided by the power steering. Moreover, the sudden change in effort required to steer could potentially lead an operator of the watercraft to believe that their steering system of the watercraft has failed and/or cause a momentary loss of control of the watercraft. It is therefore desirable to prevent the power steering from abruptly shutting off when the pump motor reaches the threshold operating temperature.
It is therefore desirable to protect the components of the power steering assembly from overheating without compromising on the safety and functionality of the steering function, and without increasing the cost and/or complexity of components of the outboard engine.